Production of mRNA's coding for transforming growth factors by selected cell lines was investigated. VSV-transformed mouse fibroblast line 3Bll-lC, human rhabdomyosarcoma A673 and human embryonic lung HEL299 have been used as source for whole cell RNA isolation. Conditions for extraction of translatable mRNA from these cell lines have been optimized for maximum translation of radiolabeled protein in rabbit reticulocyte lysate protein synthesis systems. Two approaches for monitoring TGF mRNA translation have been initiated. The production of TGFs in the in vitro protein synthesis will be of such low levels that the soft agar colony formation assay currently in use will not be sufficiently sensitive. A micro semi-quantitative assay has been developed which is capable of detecting less than 25 picograms of partially purified beta TGF. This detection level is well within the range of potential in vitro mRNS-directed TGF synthesis. Also, antibodies to beta TGF have been raised in rats which will be used to follow beta TGF synthesis by specific immunoprecipitation of the radiolabeled proteins. Either or both of these methods should allow sufficient detection and quantitation of beta TGF mRNS for further characterization and purification.